Treat gambling as a small business. Once you get your capital money back in your pocket plus 200% profit, you'll maybe use 30% of it and bet it again... if you lose, you'll try another maybe 10-20% again from your profit... and so on. it won't stop..
You can use that strategy to use 30% of your capital money to continue gamble, but you must know that when you lose, you will use the other portion of the money, and you can use the profit that you got before. If you cannot control and stop your game, you will end by losing all of the money plus the profit, so you will be sad and regret why you did that. If we talk about how much money we need to stop gambling, actually, we don't need to win much money, or if we lose, we can stop right away so we can save the rest money for another day.